Study Of Audio Digital Watermarking Technology Based On Discrete Wavelet Transform

With the rapid development of multimedia technology and computer network, the multimedia data becomes an important information source for people and becomes the important component of people's life. However, the present rapid developments of the digital signal processing and the transmission technique of computer network cause the advanced challenge of the data copyright. Thus, how to effectively protect the digital works has become one hot topic of the international researches, under the open network environment. The digital watermarking technology is one active study branch of the existing information hiding technology. The digital watermarking technology adds the special digital information to the loaded file according to a certain algorithm. Furthmore, the information is extracted and detected based on the certain method and detecting standard.This paper discusses the application information hiding technology theory and the technology of adding digital watermark in the sound document. Firstly, this paper introduces the question statement of digital watermark and correlative concept, and explains the research background and significance of the topic. Secondly, the basic principle, the model and the realization processing of the watermark algorithm are expatiated. Furthermore, by analyzing the existing studies and the current watermarking development, the studies of two digital 'audio watermarking algorithms are presented. One method is DWT algorithm embedded the synchronous signal, which is easy to extract watermark information. The other method is an algorithm which makes the DWT and DCT combined. The second method makes the multiresolution character, the partial character and the nenergy compression character combined. The multiresolution character and the partial character belong to the wavelet transformation and the the nenergy compression character belongs to the coscine transformation. The performaces of the two algorithms are adopted to vertify the transparency property and the robust of the watermark. By the above algorithms, the audio signal with watermark has better resistance.